1. Field of the Invention
The present invention generally relates to illumination for theatrical, architectural and stage lighting systems, and, more particularly, to variable beam LED color changing luminaries.
2. Description of the Prior Art
Longer life and more energy efficient sources of light have become increasingly important thus making alternative light sources important. Recent advances in light emitting diode (LED) technology particularly the development of multi-chip and multi-LED arrays have led to brighter LEDs available in different colors. LEDs are available in both visible colors and infrared. In addition to red, yellow, green, and amber-orange, which were the first available colors, LEDs are now available in blue and even white light. LEDs operate at lower currents and yet produce 100 percent color intensity and light energy. For many applications, LEDs can compete directly with incandescent filament light sources.
LEDs emit a focused beam of color light in a variety of different angles, in contrast to incandescent filament lamps, which emit only the full spectrum of light. In order to obtain color from an incandescent filament lamp, a specific color gel or filter in the desired color spectrum must be used. Such a system results in 90 percent or more of the light energy wasted by the incandescent filament lamp. LEDs on the other hand deliver 100 percent of their energy as light and so produce a more intense colored light. White light is also produced more advantageously by LEDs. White light is obtained from LEDs in two ways: first, by using special white light LEDs; and second, by using an additive mixture of red, green and blue (RGB) LEDs at the same intensity level so as to produce a white light. With regard to the second method, variable intensity combinations of RGB LEDs will give the full color spectrum with 100 percent color intensity and light output energy. The primary colors red, green, and blue of RGB LEDs can be mixed to produce the secondary colors cyan, yellow, magenta (CYM) and also white light. Mixing green and blue gives cyan, as is known in the art of colors. Likewise as is known in the art, mixing green and red gives yellow. Mixing red and blue gives magenta. Mixing red, green, and blue together results in white. Advances in light-emitting diode technology include the development of multi-chip and multi-LED arrays, which have led to brighter LEDs available in different colors. LEDs are available in both visible colors and infrared.
LEDs are more energy efficient as well. They use only a fraction of the power required by conventional incandescent filament lamps. The solid state design of LEDs results in great durability and robustness to withstand shock, vibration, frequent power cycling, and extreme temperatures. LEDs have a typical 100,000 hours or more usable life when they are operated within their electrical specifications. Incandescent filament lamps are capable of generating high-intensity light for only a relatively short period of time and in addition are very susceptible to damage from both shock and vibration.
Incandescent filament lamps of the MR and PAR type are the best known and most widely used technologies of the architectural, theatrical and stage lighting industry. Such lamps are available in different beam angles, producing beam angles ranging from narrow spot lights to wide flood focuses. Such types of lamps are very popular because they have long-rated lives up to 5,000 hours.
Light emitting diode LED technology including white light and full color red, green, blue (RGB) tile array modules have become common in certain areas of illumination, most commonly for large scale lighted billboard displays. Such LED light sources incorporate sturdy, fast-moving and animated graphics with full color. Such flat displays offer only one fixed viewing angle, usually at 100 degrees.
Another use of fixed flat panels for LED arrays are currently used in traffic lights and for stop lights and warning hazard lights mounted on the rear of automobiles.
A recent advance in LED lamp technology has been ICOLOR MR electronic controllers introduced by Color Kinetics Inc. The ICOLOR MR electronic controller is a digital color-changing lamp, which plugs into standard MR 16 type lighting fixtures. This lamp has the advantage of using variable intensity colored LEDS with a long-life of 100,000 hours or more. On the other hand, it has a fixed LED array that is limited to a fixed beam angle of 22 degrees (SPOT). Similarly, Boca Flashes, Inc. offers a compact LED array of up to 24 LEDS in a typical dicbroic coated glass reflector. The beam angle is limited to 20 degrees.
Another LED light source is use today takes the form of a flashing warning beacon. The LEDs are arranged in a cylindrical array around the circumference of a tube base. This configuration allows for viewing from a 360 degree angle. The same configuration is also used in wedge base type LED lamps as well as in LED bulbs mounted on a standard screw base.
MR and PAR type incandescent filament lamps are able to be controlled to produce complete control of output beam angles. MR and PAR lamps are fixed focus and are not adapted to control beam angles. LED technology to date does not offer complete control of output beam angles.
Some patents that have addressed this problem are as follows:
1) U.S. Pat. No. 5,752,766 issued to Bailey et al. on May 19, 1998, discloses a focusable lighting apparatus for illuminating area for visual display. A flexible base member, shown as a cylindrical flexible base or support member 20 in FIG. 2, is supported on a housing and an array of LEDs are supported on the flexible base. An actuator connected to the flexible base is operable to move the flexible base to selected working positions so as to direct LED generated light beams normally, inwardly or outwardly. The LEDs are supported on the flexible base 20. Flexible base 20 can be deflected (see page 3, lines 45-49 and also page 4, lines 43-46) so that the optical axes 39a in a parallel mode to provide converging light beams indicated by lines 39b in FIG. 2. The bending of flexible base 20 is accomplished by actuator 28 by way of a rod 26 with a second flexed position shown in phantom line in FIG. 2. It is apparent that the range of beam angles that can be achieved by pulling or pushing flexible base 20 is limited by the unitary structure of flexible base 20. Flexible base 20 itself is described as flexible so that stretching of the flexible base 20 itself is necessary to change the diode beam angles. The material composition of flexible base 20 is described as being made of any of various polymer or elastomer materials (page 4, lines 51-62). The unitary structure of flexible base 20 creates a built-in limitation position (page 4, lines 53-62. The invention described therein has a limitation to its usefulness in the field of stage and theatrical lighting. It is also noted that the limited strength of flexible base 20 itself to maintain constant diode beam angles is compromised so that the beam angles are significantly misdirected since the diodes 22 cannot maintain constant angles relative to the plane of flexible base 20 because flexible base 20 itself undergoes a warping effect and so maintains no constant plane angle except in the parallel beam mode. Also, the number of diodes 22 that can be mounted to flexible base 20 is limited by the “relatively thin” (page 2, line 59) flexible base 20. Also, permanent molding of the light emitting elements seems necessary, which indicates a difficulty in replacing the elements when they fail.
2) U.S. Pat. No. 5,580,163 issued to Johnson on Dec. 3, 1996, discloses a plurality of light emitting elements including light bulbs and LEDs attached to a circular flexible membrane that in turn is connected to outer and inner housing that are movable relative to one another so as to flex the membrane in a predetermined manner. The inner housing is threaded into an adjusting nut that can be rotated to move the inner housing relative to the outer housing. The light emitting elements are correspondingly moved so that their collective light beams are selectively focused at a common area. In this invention, the mounting of the light emitting elements is restricted to a circular membrane. It is apparent that the number of light emitting elements are restricted. FIG. 6 of the invention shows an increased number of light emitting elements but again this view emphasizes the limitation of lighting elements available on this device. The number of elements is limited primarily by the fact that the flexible membrane can support a restricted number of light emitting elements just as a weight bearing problem. It is further noted that because of the flexibility of the membrane holding the light emitting elements, each element will to some degree be significantly misdirected because of the warping effect of the flexible membrane as it is moved between positions. Also permanent molding of the light emitting elements are discussed, which indicates a difficulty in replacing the elements when they fail.
3) U.S. Pat. No. 5,101,326 issued to Roney on Mar. 31, 1992, discloses a lamp for a motor vehicle that discloses a plurality of light emitting diodes positioned in sockets that direct the diode generated light beams in overlapping relationship so as to meet photometric requirements set forth by law. The diodes are not selectively movable to different focal areas.
4) U.S. Pat. No. 5,084,804 issued to Schaier on Jan. 28, 1992, discloses a wide area lamp comprising a plurality of diodes mounted on a single flexible connecting path structure than can be moved to a number of shapes as required. The diodes of the disclosed lamp are not collectively and selectively adjustable in a uniform manner for being directed to a common focal area.
Luminaires that include a fixed light source are often used in combination with a specially designed front lens designed to provide optical characteristics that allow for different beam angle spreads. This is true for conventional filament and arc lamp type luminaires, as well as with some existing LED luminaires.
Such beam spreads include narrow spot, spot, medium spot, wide spot, narrow flood, flood, medium flood, wide flood, and very wide flood. Because there are so many possible combinations of lenses with the one luminaire, it because awkward and cumbersome to have to change the front lens every time a new beam spread is desired. An end-user would have to stock a variety of different spread lenses in order to have the one luminaire achieve any beam spread at any given time. The inventory of lenses and the manual labor of having to change out the lenses would be still greater when groups of luminaires are used.
The same inventory and time consumption program also occurs when an end-user wants a different color beam to be projected from the luminaire, more so for conventional filament and arc lamp type luminaires than with LED color changing luminaires. To achieve the different color beam outputs for conventional luminaires, a plastic color gel medium or colored glass lens is placed in front of the light source.
Based on the above, a lighting system consisting of multiple variable beam color changing LED light source luminaires becomes desirable. U.S. Pat. No. 4,962,687 for a variable color lighting system also teaches color changing LED light sources. And U.S. Pat. Nos. 6,016,038 and 6,150,774, both for multicolored LED lighting method and apparatus, disclose color control of LEDs.
Digital communications between a remote controller and color changing LED luminaires are known and are typically performed by cable wires including parallel or serial bus, in series wiring, star network wiring, parallel wiring, FDDI ring network wiring, token ring network wiring, etc. Other forms of wired communications control includes the DMX512 protocol, x10 and the CEBus (Consumer Electronics Bus) standard EIA-600 for communications over a power line. Wireless communication control can also be used with color changing LED lighting systems, including FCC approved RF Radio Frequency and IR Infrared control protocols.
Remote control of luminaires are disclosed in U.S. Pat. No. 6,331,756 for a method and apparatus for digital communications with multiparameter light fixtures; U.S. Pat. No. 6,331,813 for multiparameter device control apparatus and method; U.S. Pat. No. 6,357,893 for lighting devices using a plurality of light sources; and U.S. Pat. No. 6,459,217 for method and apparatus for digital communications with multiparameter light fixtures. These patents are incorporated herein by reference.